Some organizations are required to reject an entire lot when one defect is found, such as with a zero-defectives program. In these cases, they would use C=0 plans, also called "accept on none" plans, which are designed to have an acceptance number (C) of 0.
You can use a C=0 plan when the following conditions are true:
- You have a specified or implied RQL and beta.
- You do not use an AQL.
If your incoming quality is very good, a C=0 plan can help you to minimize inspection quantities. However, if your incoming quality is not close to perfect, you will reject more lots and will likely inspect more total items.
Steps to create a C=0 plan
- From the drop-down list, select Create a Sampling Plan.
- In Measurement type, select your measurement type such as Go / no go (defective).
- In Units for quality levels, select the units such as Percent defective.
- In Acceptable quality level (AQL), enter a very small value such as 0.05.
Even though the AQL is not required for a C=0 plan, Minitab requires a value to run this analysis.
- In Rejectable quality level (RQL or LTPD), enter the RQL value such as 0.5.
- In Producer’s risk (Alpha), enter 0.89.
Use the highest alpha possible within the constraint of alpha + beta < 1 (100%).
- In Consumer’s risk (Beta), enter the beta risk such as 0.10.
- In Lot size, enter an optional lot size.
- Choose Options. Check Use hypergeometric distribution for isolated lot.
- Click OK.